Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Cloud Movement
Name: Stacy
Status: Student
Age: 20s
Location: N/A
Country: N/A
Date: N/A 


Question:
What mechanism causes clouds to move across the sky?
Where is this steering mechanism predominantly found?



Replies:
Dear Stacey-

In general, clouds move at a speed and direction of the prevailing wind at the altitude where the clouds are occurring. The direction and speed of the wind depends on the pressure differences between the areas of high and low pressure.

As you go up in altitue over a particular location, the winds will vary in direction and speed. Usually, the speeds increase with altitude up to a certain point, and then they decrease. Rivers of fast-moving air in the atmosphere are called "jet streams," and occur at altitudes from 25 to 40 thousand feet above the ground. Speeds in the jet stream can reach as high as 175 miles per hour or more. When clouds occur at that level, they move very quickly. The location and strength of the jet stream has a big effect on the weather at a particular location.

At a lower level, the the windspeed may be different, and the direction may be different as well. Sometimes you can see clouds at several different levels, and they may be moving in different directions.

Meteorologists track the movement of clouds continuously with satellites, and with weather balloon measurements from selected locations twice a day. This information helps the meteorologists forecast the weather.

Wendell Bechtold, Meteorologist
Forecaster, National Weather Service
Weather Forecast Office, St. Louis, MO



Click here to return to the Environmental and Earth Science Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory